Governor-valve for air-compressors.



-w. E. vEnVPLNcK. GOVERNOR VALVE FOR AIR' COMPRESSOBS:

APPLICATION FILEU OCT. I6. 1913.

Paten-ted June 6, 1916.

FISA.

invrrED STATES Palmira? OFFICE.

WILLIAM EVERETT VER IPLANCK,l F ERIE, PENNSYLVANIA, .ASSGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK.

GOVERNOR-VALVE FOR AIBf-COMPRESSORS.

Specification of Letters Patent.

Patented Junge, 1916.

Application led October 1Q, 1913. Serial No. 795,560.

l To all lwhom it may concern:

Be it known that I, VILLIAM Evniin'r'r VER PLANCK, a citizen ofthe United States, A

residing at Erie, county of Erie, State of .Pennsylvania, ,have .invented A certain new ,and useful- Improvements in Governor- Valves for Air-Compressors, of which the following is a specification.

This invention 'relates to devices for preventing an excessive pressure in a tank or reservoir for the storage of. compressed air. The obvious and ordinary way of doing this is to provide the reservoirwith a safety `valve which will open at a predetermined This device cannot be used, however, in compressors which are mechanically driven from the main engine shaft and are, therefore,

operating continuously. In order to save power when such compressors have -brought the reservoir pressure up to maximum, it has been proposed to use a pressure-responsive governor which opens an unloading valve on the compressor cylinder, lthereby opening said cylinder to the atmosphere and allowing the plungerof the compressor to reciprocate freely without doing any work or requiringany power to operate it above the negligible amount necessary to overcome the friction of the moving parts.

My invention relates to a governor valve of this kind, and its object is to provide a device lwhich is reliable and prompt in action and which will not hesitate or chatter in operation.

The invention resides in certa-in detailsof construction which will be hereinafter set l forth and particularly pointedzout in the"-v claims.

-In the accompanying drawing, Figure l is a longitudinal section of my improved governor; Fig. 2 is a longitudinal section of the unloading valve which it controls; Fig. 3

is alongitudinal section of tliegoutlelt valve of the compressor; and Fig. et is a diagram showing the connectionsl oi the various elements ofthe system.

The compressorcomprises a cylinder 1 in which a plunger 2 operates, being driven by direct connection to some moving part of a prime mover., The air'compressed at each stroke of the plunger lifts the springseated discharge valve 3 and passes through thepipe to the storage reservoir 5. Connected with said reservoir by the pipe 6 is the pressure-responsive governor 7 which,

when the reservoir pressure exceeds a safe limit, permits, the compressed air to flw through the pipe 8 to the unloading valve. This comprises a casing 9 secured in an opening in the khead of the cylinder 1. An

inwardly opening spring-seated valve 101` prevents, ordinarily, the escape of air. from the cylinders. The stem 11 of the valve has an easy sliding fit in a tubular guide 12, and

in lthe upper end of said stem isa chamber 13 exposed to the pressure of the air ad` mitted by the governor through the pipe 8. A needle valve 14 regulates the admission of air to the chamber 13, and when thus admitted the fluid pressure forces down .the

ste-m 11 and opens the 'valve 10. The air'- pushed before the plunger 2 is, therefore, no longer compressed, but escapes freely to the atmosphere through the passage 15. I havedescribed this system 'somewhat in de- ,tail in order to explain the relation thereto of the governor, to which my invention is confined. a chamber 16 containing'air at reservoir pressure. In one side of the casing is anl opening covered by'a flexible diaphragm 17 whose edges are clamped air tight by an annular cap 18, rsecured to the casing by the screws 19. At the oenterof the diaphragm is an opening whose edges are clamped between a shoulder on a'sleeve 20, having a lscrew-threaded reduced portion Q0 passing -through said opening and a cap nut 21 screwed onsaid portion VQO'and having a fian'ge 22. Alielical spring 23 abuts at one end against'said flange and at the other end iscOnfinedby a recessed'nut 24 screwing It comprisesv a .casing 7 having `intoa threaded n eck Qion the annular .cap

18and serving thereby as a means for adjusting'rthe tension ofthe spring.

.TTli`e. sleeve 2() is normally hield by the spring QS'agaiiist the inner end of a tubular member 26 which projects from the side of the casing opposite the diaphragm. The

, sleeve is counterbored or recessed at`26a to house an outlet valve 27 whose seat surrounds the central bore of the member 26'. The other end of said bore communicates withthe pipe 8, through a restricted portion 26h. The outlet valve 27 has guide' Win s 2 8 on one side and on the other side a stem'29 which passes loosely through the sleeve 20, and has a suitable head, such as the Amit 30, on its e'nd inside the cap nut21. l s

-The operation is as follows: The air entering chamber 16 passes freely through a port 31 into the recess inthe sleeve 20 and thence by .the clearance-around the valve stem 29 to the interior of the cap nut 21.A The fluid pressure, therefore, exerts an unf' balanced pressure on. the/banket the valve l' 27 to hold it to its seat, the face oi said valve being .exposed ractically to .atmospheric additional leakage hole may be provided in the pipe 8 ifdesired.I `Ascthe reservoir pressure builds up. in the chamberv 16,v the vtension of the spring 23 begins to be overcome by' the increasing pressure on the diaphi-agili, s o\.tha`tV the. sleeve 20 is moved gradually-to the right 'until it takes up the small clearance between 4its end and the head '30 on the valve stem. .Further movement is then opposed bythe spring 23. Moreover, the total'l pressure on the diaphragm is partly balanced by the fluid pressure acting onthev unbalanced` area of the back of the valve 27. The increasing reservoir pressure, how ever, soon becomes high enough for the e'ective pressure on the diaphragm to lift the valve oil its seat, and the instant it does so the chamber 26a fills with full pressure,

because the passage 26b is V so small that the l air cannot flow out of said recess as fast as itcomes in. .The pressure on the two sides of the valve 27 is, therefore, practically balanced for a moment, andthe effect of this is to throw the total pressure on the diaphragm suddenly against the spring 23, an action which jerks the valve wide open with a snap or pop action without'any increasein the air pressure in the chamber 16. There is,`therefore, no possibility of Wire drawing the air in passing through the governor valve, and the valve operates without chattering.

The reservoir pressure must be reduced quite decidedly before the spring 23 will close the valve 27 but the instant it closes, the air pressure'quickly drops in the pipe 8 by reason of leakage through the hole 32 and past the valve ll, so that the valve will be held shut by the unbalanced pressure upon its back. It is essential that the pressure in the pipe 8 be either all on or all ofi, as any intermediate pressure will result in chattering of the outlet valve. The lost `xn0 tion or clearance between the sleeve 20 and the head 30 permits the diaphragm to vibrate slightly under smlall variationsin Areservoir pressure withoutaflecting the governor valve. In practice this clearance amounts to about five one-thousandths of an inch, while that-between the-flange and 'it has taken up the clearance under the head.

The valve 27 also has a greater lift independent o the sleeve 2O by reason oi' the recess in said sleeve in which said valve is housed, and inY which it can move away `from its seat'if urged to do so by reason ot the rush oliair beneath it.

This pop action governor valve has been Lfoiind to operate satisfactorily in practice, giving a prompt and' complete relief to the pressure leaking into the pipe S-paStthe, stem 11- of the unloadingvalve. -A small.

compressor when the maximum reservoir 'pressure has been attained.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention together apparatus shown -is only illustrative, and

that the invention can be -carried out by other means.

'What I claim as new and desire to secure by Letters Patent of the United States, is

1. A governor valve for air cmnpressors, comprising a casing, an outlet valve'ha ving a headed stem., a sleeve fitting loosely on said stein and movable longitudinally thereon with some lost motion, a diaphragm secured to said sleeve, and exposed to .the fluid pres-- sure in said chamber, and a spring opposing the movement of said diaphragm.

i 2. A `governor valve for air compressors, vcomprising a. casing, a diaphragm, a sleeve secured to said diaphragm and having a flanged cap nut on one end, an outlet valve having a stem passing loosely through said sleeve and provided with a head inside said nut, and a spring abutting against the llange on said nut.

3. A governor valve for air compressors, comprising a casing, a diaphragm exposed to fluid pressure in said casing, a sleeve secured to said diaphragm and having a flange cap nut on one end, a tubular member containing a valve seat, an outlet valve cooperating therewith and having a headedv stem passing loosely Ythrough said sleeve, and a spring pressing said sleeve against the end of said tubular member.l

Ll. A governor valve for air compressors, comprising a casing, a diaphragm exposed to fluid pressure in said casing. a sleeve secured to said diaphragm and having a coun- .terbored end provided with a port, a tribu the counterbore of said sleeveand having a urgingsaid sleeve against saidtubular meml ber. l

5. A governor valve for air compressors, comprismg a casing having a tubular member'containing a valve seat and a recess below the same, means for retarding the escape of air from said recess, a valve engag ing said. seat and a diaphragm exposed to air pressure, and a lost motion connection between said valve and-diaphragm.

6. A governor valveor air compressors, comprising a casing having a tubular` mem` ber containing a valve seat and a recess below the same, a restricted passage for the escape of air .from said recess, a valve engaging said seat and a diaphragm exposed to air pressure, and a lost motion connection between said valve and diaphragm;

7. A governor valve for air compressors,

comprising a casing having a tubular member containing a valve seat and a recess beloiv the same, a restricted passage for the escape of air from said recess, a 'alve and a diaphragml exposed to air pressure, a lost motion connection'between said valve and diaphragm, an unloading valve, a pipe con veyingair pressure thereto from said re-A stricted passage, and means for quickly re` leasing the pressure in said pipe.

8. A governor valve for air compressors, comprising a casing having a tubul-ar member containing a valve seat and a recess below the same, a restricted passage for the escape of air from said recess, a. valve and 'a diaphragm exposed to air pressure, a lost motion connection between said valve and diaphragm, an unloading valve permitting a slight leakage of air past its, stem, a pipe conveying air pressure to the unloading valve from said restricted passage, and a leakage hole in said pipe.

9. In a, iuid compressor system, a compressor,la reservoir, an unloading valve for the compressor operated in response to fluid under pressure in the reservoir, and means 'intermediate said reservoir and said unloading valvefor controlling the admission of fluid from the reservoir to the unloading valve comprising a valve and means for substantially equalizing the pressure on both sides of said valve when it is opened.

10. In a fluid compressor system,a compressor provided with an unloading valve, a reservoir connected with said compressor, means intermediate said reservoir and said unloading valve, acting in response to the pressure in the reservoir for opening said unloading valve and comprising an outlet valve for controlling the admission of fluid from the reservoir to the unloading valve, said outlet valve being normally seated by an unbalanced pressure, and means for substantially` equalizing the pressure on both sides of the valve as soon as itis unseated.

In witness whereof, I have hereunto set my hand this 13th day of Qctober, 1913.

WILLIAM EVEltET'l VER PLANCK.

Witnesses O. T. FOUGHE, HERMANN Lia-Mr. 

